With the development of data storage techniques, various data storage devices now provide users with higher and higher data storage capacity, and also their data access speed has been increased greatly. Besides the increase of data storage capacity, users also impose greater and greater demands on data reliability and response time of storage systems.
So far various data storage systems based on redundant arrays of disks have been developed for improving reliability of data. When one or more disks in a storage system fail, data in failed disk(s) can be recovered from other normal disk. However, in the rebuilding process for data recovery, data access requests received by the storage system will take up various resources in the storage system, and further interfere with the rebuilding process. Therefore, it becomes a focus of research regarding how to manage the storage system more effectively and alleviate interference of data access requests in the rebuilding process.